Phenylbutazone-sodium-monoglycerate

ABSTRACT

PHENYLBUTAZONE-SODIUM-MONOGLYCERATE IS PREPARED IN CRYSTALLINE FORM; THE COMPOUND IS COMPRISED IN PHARMACEUTICAL COMPOSITIONS AND HAS ADVANTAGEOUS PROPERTIES IN THE TREATMENT OF INFLAMMATORY DISEASES.

of the 3",5-dica rbonyl grouping, Water-soluble salts. The 45 of its poor crystallising property and its hy-groscopicity,

'duction of dry ampoules in any way other than by the 55 relativelyexp'ejnsive process of dry freezing (lyophilisa- United States Patent ice Patents, 2322 3 932 sodium salt is produced, e.g. by concentrating by evapora- 3,644,395 tion its ethanolic solution, prepared from equimolecular PHEPIYLBUTAZONFSODIUM'MONOGLYCERATE amounts of phenylbutazone and sodium ethylate, or by l g y b fi f i g gi i g concentrating by evaporation its aqueous solution, pre- "SIgHOI o eigy emica orpora on s ey Drawing Filed Dec. 5, 1969 No. 885,693 5 pared from phenylbutazone and sodium hydroxide solu Cl i priority application Switzerland, 11, 1963, tion; no further purification is obtainable by recrystallisa- 18,458/68 tion of the sodium salt.

I t, Cl, (107d 49/08 Surprisingly, it has now been found that equimolecuj 1 Claim lar amounts of phenylbutazone ions, sodium and glyc erin form a very well crystallising compound of phenylbutazone-sodium-monoglycerin of the Formula I UisQcl. 260- 311 ABSTRACT OF TIE DISCLOSURE ,Phenylbutazone-sodium-monoglycerate is prepared in O crystalline form; the compound is comprised in pharma- NJ$ CHg-OH ceutical compositions and has advantageous properties I e in .the, treatment of inflammatory diseases. I

' -NC H3-OH DETAILED DESCRIPTION H This formula is meant to indicate only that, in the stated 'The present invention relates to a crystal compound crystal compound, the sodium is present as a cation and of phenylbutazone, a process for the production thereof, the phenylbutazone as an anion, and that the ratio of as ,well asmedicamentscontaining the compound and the 3 components is equimolar. It is, however, thereby their; use. v not defined, in What proportion of the mesomeric forms:

It is known that the antirheumatically active substance 4-nbutyl 1,2 diphenyl 3,5 g pyrazolidinedione for the anion of the phenylbutazone is present. whichm the follow ng the generic name phenylbuta The crystal compound of the Formula I, i.e. the phenyl- 1s used, forms with morgamc and organlc bases, by virtue butazonbsodiummqonoglycerate crystallises Well from aqueoushsioluifion of the pharmaceutical, acceptable ganic and organic-aqueous solvents and can therefore .dium salt-has for a long time been used for intramuscular eaSllY be Obtained in P formon the other hand, it is i j o i other hand, hes m Salt, y reason readily soluble in water, is reabsorbed well by mammals and is also suitable for the rapid preparation of aqueous tqgfither Wlth the assoclated dlfii-culty of obt exact solutions of the sodium salt of phenylbutazone, e.g. as the dosages, and also by reason of its low storage stability, is

veryunsuitable for' the production of solid oral dosage active substance for y mpoules. The crystal comunits such as tablets; drages and capsules. Moreover, pound of the Formula I also has good stability in Storage it is likewiseunsuitable as active substance for the prod i only slightly hygroscopic It can th f be weighed off satisfactorily and is miscible with the usual ntion) the'individual ampoulesl Furthermore the purity of carriers for solid oral dosage units, so that it is extremely e sodium a the m only col-respond to that suitable as active substance for such oral preparations. of the'starting materials used to form the salt, when the Using the process according to the invention, the phenylbutazone-sodium-monoglycerate of the Formula I is produced by reacting phenylbutazone of the Formula II A with glycerin and a substance releasing sodium ions, with a pH-value above 7, optionally in the presence of organic or organic/aqueous solvents, separating the phenylbutazone-sodium-monoglycerate which has precipitated in crystalline form and, optionally, recrystallising it from a suitable solvent.

The reaction is performed using dissociating sodium compounds with any anion, but preferably with anions which form weaker acids than the phenylbutazone. It is possible to use, e.g. sodium hydroxide solution, sodium carbonate, sodium alkanolates such as, e.g. sodium ethanolate or a glycerin sodium salt.

The smooth course of the reaction is not impeded by the addition of solvents such as water, lower alkanols such as, e.g. ethanol or isopropanol, as well as aromatic solvents such as, e.g. benzene or toluene, or mixtures of these solvents, provided that the concentration does not fall below the solubility product of the phenylbutazone-sodiummonoglycerate.

The precipitation of the phenylbutazone-sodium-rnonoglycerate occurs as soon as the three reactants, phenylbutazone, sodium ions and glycerin, come together in alkaline medium, in any sequence or simultaneously and in suflicient concentration, whereby the minimum concentration to be exceeded is affected by the type and amount of the solvent.

,Thus, the phenylbutazone can for example be suspended or dissolved in one of the stated solvents or mixtures of solvents, whereupon sodium hydroxide and glycerin can be added, successively or simultaneously, or a glycerin sodium salt.

The procedure can however be such that, for example, phenylbutazone and sodium hydroxide are together put into one of the stated solvents and then reacted with glycerin.

It is however also possible to dissolve phenylbutazone in dilute sodium hydroxide solution, in the presence or absence of solvents, and to then react the solution with glycerin.

Instead of sodium hydroxide solution, a solution of sodium in a lower alkanol can be used, which is reacted with phenylbutazone and glycerin. Alkanol and phenylbutazone 4 can however be added to glycerin with subsequent reac: tion with sodium hydroxide.

A further embodiment of the process consists in adding, in a continuously operating Oslo-crystalliser, the three reactants simultaneously, in stoichiometric amounts, to the solvent or mixture of solvents, containing excess of glycerin.

The crystals, preferably precipitating upon cooling, are separated and optionally recrystallised from organic or organic-aqueous solvents or mixtures of solvents.

Suitable organic solvents are lower alkanols such as methanol, ethanol or isopropanol, and aromatic hydrocarbons such as, e.g. benzene or toluene.

In the same manner are obtained from the mother liquors, partially concentrated by evaporation, crystals of the phenylbutazone-sodium-monoglycerate.

It has now been established that the crystal compound of the Formula I, according to the invention, possesses a surprisingly good reabsorbing capacity. Thus, the phenylbutazone-sodium-monoglycerate attains, in the case of oral administration to dogs, a higher level in the blood than equimolecular amounts of phenylbutazone. Advantageously, the higher level in the blood of the phenylbutazone-sodium-monoglycerate is attained more rapidly than with phenylbutazone.

The reabsorbing capacity was determined in a crossover test on dogs. Dosages of 50 mg./kg. of phenylbutazone and the equimolar amount of 68 mg./kg. of phenylbutazone-sodium-monoglycerate were administered in capsules, in each case, to 10 dogs. Five dogs firstly received phenylbutazone and 3 weeks later phenylbutazone-sodiummonoglycerate, Whilst the other five dogs firstly received phenylbutazone-sodium-monoglycerate and 3 weeks later phenylbutazone.

After administration of the substances, samples of blood were taken from the dogs at specified intervals of time 4, 1, 2, 3, 4, 8 and 24 hours), heparin was added and the samples were then frozen until a test series was complete. The phenylbutazone content g/ml. of blood) of each sample was determined according to the method of J. Burns et al., J. Pharmacol. Exp. Therap. 113, 4-81 (1955) and the results are given in the following Table l and Diagram 1.

Diagram 1 shows the mean values and standard variations of the phenylbutazone content g/ml.) in the blood in relation to time. From this is seen that, after oral administration of phenylbutazone-sodium-monoglycerate, the content of phenylbutazone in the blood (pg/ml.) increases more rapidly and attains a higher value at an earlier stage than after oral administration of the equimolar amount of phenylbutazone in animal tests.

TABLE 1 Level of phenylbutazone in blood ug/m1.) in the case of dogs after oral administrationof 50 mgJkg. of phenylbutazone I and 68 mgJkg. of phenylbutazone-sodium-monoglyccrate II] Time Compound hr. 1 hr 2 hrs. 3 hrs. 4 hrs. 8 hrs.

Mean value 20. 7 41. 1 75. 0 82. 3 91. 3 72. 9

1r s. 4 5. 4 34. 9 63. 2 59. 5" 86. 7 I

Mean value 48. 6 80. 6 105. 1 95. 5 89. 8 69. 9

.lg/inl. blood] Phenylbutazone x h rhexgylbutazone godrumn monoglycerate l a v w A 112 I. 2-

Hours The phenylbutazone-sodium-monoglycerate is preferably administered orally or parenterally.

The daily dosages of the compound of the Formula I, to be taken internally for the treatment of rheumatic, arthritic and other inflammatory diseases, vary between 150 and 1200 mg. for adult patients. Suitable dosage units such as drages, tablets and capsules, preferably contain 50-200 mg. of phenylbutazone-sodium-monoglycerate.

Dosage units for oral administration preferably contain between and 90% of active substance. They are produced by combining the active substance, e.g. with solid, pulverulent carriers such as lactose, saccharose, sorbitol, mannitol; starches such as potato starch, maize starch or amylopectin, also laminaria powder or citrus pulp powder; cellulose derivatives or gelatine, optionally with the addition of lubricants, such as magnesium or calcium stearate or polyethylene glycols having suitable molecular weights, to 'form tablets or drage cores. These are coated, for example, with concentrated sugar solutions which can also contain, e.g. gum arabic, talcum and/or titanium dioxide, or with a lacquer dissolved in easily volatile organic solvents or mixtures of solvents. Dyestuifs can be added to these coatings, e.g. to distinguish between varying dosages of active substance. Other suitable dosage units for oral administration are hard capsules made of gelatine, as well as soft closed capsules made of gelatine and a softener such as glycerin. The hard capsules preferably contain the active substance as a granuing to 5, the crystals are rfiltered with suction, washed magnesium stearate and, optionally, stabilisers such as Example 1 To a stirred suspension of 37 g. of finely ground phenylbutazone in 'water are added 5 g. of solid sodium hydroxide. Stirring is continued at room temperature for about half an hour until a clear solution is obtained, whereupon 100 g. of glycerin are added. The solution is stirred and slowly cooled to 2. After about 4 hours, 46.1 g. (91% of theory) of crystalline phenylbutazonesodium-monoglycerate are separated by filtration or centrifugation; M.P. 205-210".

Example 2 2.3 g. of sodium are dissolved in 100 ml. of isopropanol. 30.8 g. of phenylbutazone are added at and to the obtained clear solution are added 9.2 g. of glycerin, whereupon crystallisation immediately occurs. After coollate in admixture with lubricants such as talcum or with ice cold isopropanol and dried at 60 under 0.1 torr.

33.7 g. of phenylbutazone-sodium-monoglycerate, M.P. 205210, are obtained.

Example 3 9.2 g. of glycerin are added, while stirring and at room temperature, to 100 ml. of isopropanol. 30.8 g. of phenylbutazone and 4 g. of sodium hydroxide are then added and the reaction mixture is heated, while stirring, to 80. Upon cooling, phenylbutazone sodium monoglycerate crystallises out from the clear solution. 32.4 g. are obtained, M.P. 205-210.

Example 4 Purification of the crude product, obtained according to 'Examples 1, 2 and 3, can be carried out as follows:

Example 5 137 g. of phenylbutazone-sodium-monoglycerate are mixed with 2.2 g. of highly dispersed silicon dioxide, 118.4 g. of lactose and 4.4 g. of magnesium stearate in a suitable mixer to obtain a homogeneous powder. If necessary, the mixture is put through a sieve to attain a uniform particle size and again mixed. The mixture is filled into 1000 hard capsules in the usual manner. Each capsule contains 262 mg. of the pulverulent mixture and 137 mg. of active substance.

Example 6 11370 g. of phenylbutazone-sodium-monoglycerate are mixed with 1096 g. of secondary calcium phosphate, 1096 g. of lactose, 1370 g. of maize starch and 109.6 g. of highly dispersed silicon dioxide in a suitable mixture to obtain a homogeneous powder.

1096 g. of a suitable binder (e.g. Arnijel Boll.) are mixed .vvith hot water at to form a paste of 6. 67% by weight. This paste is then granulated together with the powder produced as described above" and, if necessary, water is added. The moist granulat'e is granulated through. a sieve No. III (Ph.Helv.V), dried in a suitable drier at 40 C. to obtain a moisture content of 13%, and then put through a sieve No. IIIIIIa. 32.9 g. of magnesium stearate, 32.9 g of highly dispersed silicon dioxide and 263 g. of maize starch are added and the whole is mixed for 10 minutes. The mixture is pressed into 10,000 tablets, each weighing 548 mg. and each :containing 137 mg. of active substance. Optionally, the'tablets can 'be provided with grooves for finer adjustment of the dosage amount.

What we claim is:

1. Phenylbutazone sodium monoglycerate having the Formula I x cs -on I CH-Oll Na n en cn cu sa -on 1) References Cited UNITED STATES PATENTS 2,562,830 7/1951 Stenzl 2-60310 3,487,046 912/ 1969 Negrevergne 26051.5 3,491,190 1/1970 Rumpf et al. 424- 273 FOREIGN PATENTS 'M4,183 5/1966 France 260311 HENRY R. IILES, Primary Examiner G. T. TODD, Assistant Examiner US. Cl. X.R. 

